why to the same versions of clang

[Tijl Coosemans]

On Sat, 16 Nov 2013 07:10:14 -0500 Ajtim wrote:
> I like to know what is different with default clang on FreeBSD
> 10.0-BETA3 and cland from /devel.  I like to install blender and
> graphics/blender and graphics/openshadinglanguage need/wanted clang
> from /devel. The same version as I have:
> clang -v
> FreeBSD clang version 3.3 (tags/RELEASE_33/final 183502) 20130610
> Target: x86_64-unknown-freebsd10.0
> Thread model: posix

The LLVM in base only provides what's needed for Clang.  In fact there
are no LLVM libraries and tools installed at all.

So ports that use LLVM like openshadinglanguage (which is essentially
a compiler implemented on top of LLVM) need to depend on one of the
LLVM ports.  This particular port also uses clang to compile some C++
code into LLVM bitcode and this bitcode needs to work with the version
of LLVM that it uses.  Currently you could use base system clang for
that because the versions are the same, but when FreeBSD switches to
Clang/LLVM 3.4 that will no longer be the case.